This invention relates to a method for the manufacture of nickel boride colloid which possesses a remarkably high catalytic activity in the hydrogenation of carbonyl compounds.
Heretofore, nickel boride has been used such as in the form of a fine powder which is obtained by the reaction of sodium borohydride upon a nickel salt solution (Ind. Eng. Chem., 44, 1006 (1952)) or in the form of a homogeneous colloidal solution which is obtained by the reaction of sodium borohydride upon a nickel salt in an alcohol solvent in the presence of a suitable polymer (Chemistry Letters, 995 (1979)). It has been known to exhibit a high catalytic activity comparable to the activity of Raney nickel in the hydrogenation of a carbon-carbon double bond.
These forms of nickel boride which have heretofore been used exhibit a decidedly lower catalytic activity in the hydrogenation of unsaturated bonds other than the carbon-carbon double bond, such as, for example, the carbon-oxygen double bond. Under the conditions of normal room temperature and atmospheric pressure, they produce substantially no catalysis in the hydrogenation. The hydrogenation of a compound possessing a carbon-oxygen double bond, namely, a carbonyl compound, for the production of a corresponding alcohol is a reaction of great industrial significance. This reaction generally relies upon Raney nickel catalyst. Nevertheless this catalyst entails rigid conditions of elevated temperatures and high pressure for effective performance.